package com.lagou.api;

import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.ZooKeeper;

import java.io.IOException;
import java.util.concurrent.CountDownLatch;

public class CreateSession implements Watcher {

    private static CountDownLatch countDownLatch = new CountDownLatch(1);

    /**
     * 建立会话
     */
    public static void main(String[] args) throws IOException, InterruptedException {
        /**
         * 客户器端可以通过创建一个zk实例来连接zk服务 new Zookeeper(connectString,sesssionTimeOut,Wather)
         *      connectString: 连接地址：IP：端口
         *      sesssionTimeOut：会话超时时间：单位毫秒
         *      Wather：监听器(当特定事件触发监听时，zk会通过watcher通知到客户端)
         */
        ZooKeeper zooKeeper = new ZooKeeper("192.168.44.128:2181", 5000, new CreateSession());
        System.out.println(zooKeeper.getState());

        // 计数工具类：CountDownLatch:不让main方法结束，让线程处于等待阻塞
        countDownLatch.await();

        System.out.println(zooKeeper.getState());
        System.out.println("客户端与服务端会话真正建立了");
    }

    /**
     * 回调方法：处理来自服务器端的watcher通知
     */
    public void process(WatchedEvent watchedEvent) {
        // SyncConnected
        if (watchedEvent.getState() == Event.KeeperState.SyncConnected) {
            //解除主程序在CountDownLatch上的等待阻塞
            System.out.println("process方法执行了...");
            countDownLatch.countDown();
        }
    }

}